Nutritional Revolution Podcast

Pushing Limits: Inside a Landmark Study on Female Ultra Endurance Athletes

• Season 6 • Episode 178

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In episode #178, we spoke with Dr. Trent Stellingwerff and Susan Boegman about their groundbreaking research on ultra endurance athletes, featuring unprecedented data on female participants. Discover how energy expenditure, nutrition, biomechanics, and recovery strategies come together in one of the most comprehensive multi-disciplinary studies in endurance sports.

In this episode:

  • The physiological and psychological effects observed during extended endurance events
  • Unique findings on body comp changes, neuromuscular fatigue, and hydration dynamics
  • Implications for athletes, coaches, and sports scientists supporting ultra endurance performance

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Hello, everybody. On our next episode, we brought on two incredible researchers to talk about Project Further, a study looking at women ultra runners during a six-day ultra event. Dr. Trent Stellingwerff and Susan Boegman together bring an incredible wealth of information and research on ultra endurance athletes. Susan Boegman is a high-performance certified senior practitioner with OWN, the podium sports scientist Canada, and is the nutrition lead for the Canadian Sport Institute Pacific in beautiful British Columbia. an organization that delivers health and performance solutions to Canadian Olympic and Paralympic athletes. She has provided integrated nutrition support as part of the CSI Pacific Sports Science and Medicine teams for many national sport organizations, including swimming, rugby, triathlon, rowing, and soccer over the past five Olympics. Although her work is primarily applied, she contributes to athlete-centered research as part of the national teams and in support of the CSI Pacific Innovation and Research team. Prior to focusing on sport, Susan worked as a nutrition counselor within a highly specialized eating disorders program. Susan is a registered dietician with the College of Dietitians of British Columbia and has a bachelor of science from the University of Alberta. Is a level two certified anthropometrist with the International Society for the Advancement of Anthropometry and is a contributing lecturer for the prestigious International Olympic Committee's Sports Nutrition Diploma. Dr. Trent Stellingwerff brings decades of leadership across various aspects of high performance sport, science and research, particularly in exercise, physio and sports nutrition to his current role as director of R &D at the Women's Health Sports and Performance Institute. Dr. Stellingwerff still retains a smaller position as a senior advisor of R &D at the Canadian Sport Institute. Pacific, where he has worked since 2011. Over the years, he has overseen multidisciplinary health and performance teams, led major R and D initiatives and supported national Olympic Paralympic team athletes in track and field, rowing, triathlon, and mountain biking. He's contributed to more than 160 peer reviewed publications, co-authored international consensus statements, including guidelines with international Olympic committee, world athletics, world aquatics, and Union Cycliste Internationale. He is a member of the International Advisory Board for the International Olympic Committee's diploma program in sports nutrition and SNC programs and currently co-chairs Canada's national working group on relative energy deficiency in sport. His recent work centers on advancing the science of female athlete health and performance. Dr. Stellingwerff's academic background spans leading institutions in human performance and nutrition. He completed his Bachelor of Science in Nutrition and Exercise Physio at Cornell University and earned his PhD in Human Exercise and Skeletal Muscle Physio from the University of Guelph, followed by a postdoctoral fellowship in Exercise and Muscle Physio at the University of Maastricht as the WHSP Director of Research. Dr. Selenworth guides the Institute's strategy, research agenda, and cross-disciplinary collaborations, helping to build the evidence base that elevates care for female athletes everywhere. This was a super fun episode. Enjoy the listen. Hello everybody and welcome back. We have for you guys, Susan Boegman and Trent Stellingwerff. Thank you so much for joining us. It's a mouthful, spelling that in kindergarten is hard. So yeah, we're happy to be here. I'm excited to have you guys. We are going to talk all things about the Further study, but before we dive into that, I'm going to have Susan, I'm going have you start with your two truths and a lie. Okay. Awesome. Okay. So because I am a nutritionist, a diet sport dietitian, I decided to go with food. So the world consumes an estimated 50 billion burgers a year. Yeah. All of the further athletes ate burgers during the event. Okay. And the classic burger, the beef patty, lettuce, pickles, and cheese is known as the California Burger. We were in California after all, so let's go. Okay. I love it. And then, okay, maybe I want, are these stumping you Trent? I'm just curious. Okay. Yeah. You are good. the classic burger is known as the California burger. Is this by a specific restaurant chain or is this like a known? just, I mean, it potentially is a known fact. Okay, okay, I see, I see. Don't wanna reveal anything. I mean, I have seen endurance athletes eat burgers and pizzas and I mean, sandwiches while they're out there doing stuff. So I definitely think that could be feasible for sure. The world consumed 50 billion burgers a year. I also unfortunately could see that being true. Yeah, I mean, maybe it's even, maybe it's more than that. Maybe there's a number fudging there. Okay, so I think maybe that's what I'll do. I'm going to go with the world consume 50 billion burgers a year as the lie because maybe there's like a different number situation there. And then Trent, I'm going to have you break down your two truths and lie. Yeah, mine's a lot more personal, so you're get a laugh out of this. during the peak of the Seattle grunge rock era 30 years ago, when I was in university, I had dreadlocks, six tattoos, and a nipple piercing. Are these all the truths and lies? All right. This you cannot probably find on Google, huh? Yes. Okay. Well, this is a tough one. Is this stumping you, Susan? I know one of them, but I'm not sure about the other two. Yeah. I this is this is a good one, Trent. I'm gonna again, I'm kind of like a number thing. I'm gonna go with the six tattoos. I think is a lie. I think maybe you did have a nipple piercing. Maybe you had dreadlocks. But maybe it's like five tattoos or something like that. I'm gonna think those are the lies. The number number ones. But for our listeners, we will find out if Trent had a nipple piercing at the end of the episodes. You're gonna have to hang on there and em how many burgers the world eats in a year. We'll find out. All right, so to kick things off today, I'd love for you guys to share and maybe we can start with Susan, your current roles and how you guys split your time between your applied work with athletes and then the research lens here. So I currently work as the lead for sport nutrition at Canadian Sport Institute Pacific. But most of my work is field work with the athletes. So it's applied rather than research. So a big job of supporting health and performance. And I would say that most of the work involves like assessing the athletes needs and any gaps that they might have and then helping them also make sense of all of the research that Trent is doing or maybe other people, for example. and just helping them understand what's actually key for them or important for them and their sport. And then also just a lot of GI work, helping them understand physiological data that Trent, for example, does and how that impacts their metabolic fuel use. And then translation of that into simple fueling strategies. I work with lot of endurance athletes and they have a struggle often to get enough. calories every day. And then sometimes I get the joy of jumping on a research project with Trent and I would say maybe that's about 10 % of what I do. for example, CSI Pacific and Trent did a REDS project, which we were part of. And then we recently did some altitude assessment of altitude impact on energy availability in REDS up at altitude with rowing. And so I was involved in that project. So that's. that's the really cool stuff as well. yeah, but that's about 10%. Yeah. very neat, very neat. And then Trent, what about you? Yeah, so I'm currently the Chief Performance Officer at the Canadian Sport Institute Pacific where, Susan and I have been colleagues for many years and we're just down the hall from each other. And we're one of the Olympic and Paralympic training centers here in Canada based in Victoria. And so the majority of my previous background is physiology and nutrition and working mainly in endurance sport as well. But then over the last three or four years, I've transitioned much more into the area of research and help lead, co-lead our research and development team at the Canadian Sport Institute. So adjunct to a couple of universities, we have grad students doing different projects in different places, and then also work with some industry partners to do research as well. Neat, okay. And Trent, what got you interested in the ultra endurance space? Yeah, I think overall this is over the last 15 years, maybe the third research project that I've been involved with in the ultra endurance space. ah first of all, when this came up and we'll hear a little bit more about the story, to be involved in doing a research project around a six day ultra was just so incredible and unique. But first of all, there's barely any six day ultras. Like if you look at the race calendar as a percentage, there's only a handful around the world. Most of the research data is based on 50, kilometer, 100 kilometer and 100 mile races, not multi-day races. So there's a lot of unique factors that were really interesting here. You know, we're to cover it a bit more later in the podcast as well, I believe, but the ability to design and support these athletes and design a research project that was going to be field-based was especially interesting and exciting. And then finally, You know, when we think about ultra endurance compared to other sports, there's so many other intangibles that we need to think about and measure and appreciate that influence health and performance. One being nutrition. it's nutrition is so important in ultra performance and given Susan and I's background that that's a really easy and positive fit, but also every ultra course has different terrain, different weather conditions. You've got to think about altitude. You've got to think about sleep deprivation and, nutrition and hydration challenges, overuse injuries that may happen during the event itself, strategies on pacing, circadian rhythms. And so when you think holistically around all the different disciplines and factors of health and performance, like every single, almost every single one of them came into this project. it was a big, stressful, audacious project. but we had an amazing group of researchers and staff to be able to. It is really, yeah, lot. Yeah, this is so fascinating. I think the endurance space within the ultra endurance space is getting bigger. And then the research on that area. Yeah, we just we don't know. We need more, which is that's why I'm super excited to have you guys here. So there was a study that got produced, The ad libidum diet, energy availability, body competent performance in females during a six day ultra marathon. And that Can you tell us about that? That was the further study? That's the information you guys collected from the further study? Yeah, so what you've read there is actually just a published abstract. So at the American College of Sports Medicine earlier this year was the first conference in May that about a year later that we've pulled together and analyzed all the data. And then Dr. Alex Coates presented that abstract at the American College of Sports Medicine. yeah, it was titled at Libidum diet, energy availability, body comp and performance in females over six days. That is but one of the questions. And so oh I think it's important to highlight that we had at the event 28 different research scientists and students involved to pull off six days of continuous research. And actually in the end, it was about 10 days of continuous research because we pre-testing and post-testing. And I'll just highlight that we had six different research groups involved. um And I do want to say a few names here. Alex Coates and Jamie Burr led the physiology group. We had Chris Napier lead the Biomech group. had neuromuscular and cognitive fatigue led by Dr. Nicky Bruce and Chris McNeil. The energy group by Dr. Sarah Purcell and Susan, and then the psych social group led by Dr. Erica Bennett at University of British Columbia. so, you know, the overall was what are the multi-dimensional, multi-factorial determinants of health and performance over six days? Mm-hmm. And again, this is pretty rare to have everything from a biomechanist, you know, numbers and math, and then Erica Bennett on psych social research, all in the same room, participating on the, the same research project. So there were tons of sub questions. I'll just highlight a couple, you know, from Erica Bennett's, Dr. Bennett's perspective, one of the exploring women's ultra runners, psych social experience of pain, body image, coping, and self-regulation was, was her main research agenda. um But then from the biomechanics perspective, that's Dr. Chris Napier and his crew was doing full body kinematics and kinetics evolve and change over fatigue. So do you're running biomechanics? um What do they look like between athletes, but also with within an athlete over six days? So again, it was a big project, um lots of um discussions. um And yeah, Susan was really intimately involved in the energy team and energy intake team, um helping support athletes directly in their feeling questions and their crews, but also trying to measure every single gram that they all ate throughout the whole event too. Gosh, that sounds like a task to measure all that. What was the nutrition question going into this, Susan? Oh, well, we were looking at um energy availability and we were looking at energy balance, energy intakes and energy deficits. We were trying to basically characterize um carbohydrate intake, protein intake, fat, so all of the macros, whether or not the athletes were able to support the fueling over the course of the six days, what kind of an energy deficit there was. So there was a lot of questions that came out of that and still some interesting things to be published for sure. Yeah. gosh, fascinating. OK. Well, we will learn shortly in the episode how all this data was collected. But Trent, for you, what was the reasoning behind choosing a multi-day event versus a single day event? And you kind of touched on it a little bit, or even a lab-controlled setting to look at some of this information. Yeah, I think most athletes and coaches and most applied sport researchers and sport scientists are most interested in high ecological validity and high ecological validity really is how transferable are the results to your environment and your reality. And so these training camp study approaches are the best, the very best we can do to measure using best practices, methods and protocols. what is going on, um but they're placed in the field or the field of play for athletes. so getting them out of the lab as much as possible and in the field of play and measuring what was happening out on this um two and a half mile loop for six days was really, really important to us. That said, I will highlight there was some lab based work. Like we have assessments done on the athletes already a year, a year and a half in advanced. you laboratory conditions up in Canada at our lab when the athletes came up to visit several times. So there was some lab-based pieces. In the three days leading in, we transported part of an entire lab down from our institute to the hotel, next pretty close to the course. And so we did all the baseline testing in a hotel conference room. So that was lab-controlled type testing, blood work. Exascans using all the best practices. But again, that was set up all remotely in a hotel next to the course. Wow. Gosh. Hey everyone, when's the last time you actually looked under the hood with comprehensive blood work? Most of you are training 10, 15, 20 hours a week, but have no idea if your body has what it needs to perform. Here's what we see constantly. Low ferritin tanking your aerobic capacity, vitamin D deficiency that's increasing your injury risk or keeping you sick, elevated cortisol from over-training, thyroid markers that are normal but not optimal for an athlete. So that's why we created our full athlete blood panel. We test everything, complete metabolic panel, advanced lipids, iron stores, vitamin D, B12, folate, magnesium, testosterone, cortisol, thyroid, insulin, hemoglobin, you name it, it's over 20 markers that directly impact your performance and your recovery as an athlete. It's $371 and includes the lab fee through Quest, and you can get tested as soon as tomorrow morning. Check the show notes for the link to order. Some state restrictions do apply, but it's available in most of the US. Stop guessing and get the data. And can you tell us a little bit about the study genders that were participating, age ranges, things like that? you bet. So there's very little in the literature at all on multi-day ultras, let alone multi-day ultras with just a female cohort. So this is, I believe, the only multi-day ultra that's not a case study in female athletes. So that was super unique to be able to address through multifactorial ways what was going on. so Leading into this though, obviously we had an industry partner involved and it's really important to highlight Lululemon's sponsored this and this project doesn't happen without an industry partner and their backing behind all the research that went into it. They put a lot of their own people and their own passion and their own resource into this project and these athletes were all sponsored by Lululemon to be part of the project as well. Beyond that, there is emerging evidence in the literature and some evidence been there for 20 or 30 years that females compared to males might have certain physiological or psychological advantages for ultra endurance. And therefore, the typical world record gap between males and females is in running events is about 10%. And perhaps there's a way that over these ultra endurance events that, know, females can bridge the gap and close the gap down to five or 7%. And there's certainly examples in small, smaller fields of women winning ultra races outright, over males as well. And, and so, you know, a big part of that without getting too deep into all the physiology and everything else is on average women have 15 to 20 % greater prevalence and are cross-sectional area of, slow twitch muscle fibers. so to which muscle fibers fatigue glass, they're more resilient. They result in less muscle damage and quicker recovery. They also result in less carbohydrate use, so more fat metabolism. And when you're looking at the determinants of ultra performance, just from a fiber type perspective, all of those things are really important and positive to have. But conversely with, you know, another example is there's also amazing data on that women can pace better than men. they probably have less ego involved, a little more pragmatic and realistic around their pacing, you know? So. There's several reviews that have highlighted this and so that also was part of the interest in focusing on females. And certainly to bridge the gap and there's barely any research on female health and performance and that was a big piece of it as well. Yeah, I absolutely love that. em So and there was how many participants in the study? we had 10 women and they not only did they all start, but they all completed. And so I feel like we're all pretty proud of that. And, you know, I think just to speak to the fact that they were from all over the world, like we had from the US, from Korea, China, Japan. So that was pretty exciting, although it did sometimes pose some challenges too. And we definitely had some needed an interpreter, for example. And there was a wide variety of ages, like age 27 to 48. So we had a big age span. And then we also had quite a variety of training and performance levels as well. Yeah, I'd love to know that because didn't the participants, did they set their own goal for the six days? Can you tell us about that as well? Well, so probably the best person to tell us about that would be Dr. Charlene Orr, who is our lead for mental performance at the time. And she sat down with the athletes and did chat with them about what their goals might be. So they were all individual based on where they were coming from. So, for example, we had four athletes that were professionals. Three of them were elite ultra marathoners and we had one athlete who was what we would call a tier five athlete and she was a world record holder. And then we had six athletes that we would call trained or developmental and one of them in fact had only started running for the project. She literally decided to sign on not having run a step and then she trained for an entire year beforehand. So that is so her I think every athlete had pretty audacious goals. We had one athlete who wanted to break the men's record and we had another athlete who wanted to run 50 kilometers a day every day for for six days for example. So yeah and I guess the one note I did mention tier so we had like four athletes that were tier four athletes and a tier five athlete and then we had tier two athletes. What's important about that I think is just thinking about the the athlete classification allows us when we're doing research or when we're interpreting research to understand the research better. So, you know, if you're looking at research and it's on tier one athletes or developmental athletes that might not apply to a tier four or five athlete and Trent was integral on doing that classification. And so I don't know if that's a good link to the show notes, but I think it's really important for us when we're talking about athletes to understand the caliber of athletes that we're paying attention to and evaluating. So yeah, so we had a wide range. We had a wide range of athletes participate. I love that end age range. the tiered, how, for our listeners, how would you describe that? What is a tier one athlete versus, I think you said a tier five, Susan, like, what does that mean? would be a world class athlete and a tier one athlete would be a very new developmental athlete. And then and then running in between. Gotcha, okay, that's helpful. So, and it's not necessarily based off of like a VO2 max or anything like that. No, okay. Awesome. So you guys monitored a bunch of things. Susan, you mentioned measuring all the food, energy availability. Trent, was there also like core temperature sensors or sweat testing? What other things are you guys measuring throughout this study? We threw the kitchen sink at them as much as what was feasible and possible. Well, at the same time, our number one ethos is they are there to compete and we can't be a distraction. so, yeah, like going, you know, down the list of things, it was extensive and it has become more extensive the last 10 years or so, primarily due to the fact that there's been an explosion of wearables that people can use and implement into racing. So, you know, very quickly in the two to three days leading into the event, when everyone is there at rest, did a submeximal VO2 max test. We did body composition by DEXA, blood collection, hemoglobin mask, baseline fresh, neuromuscular and cognitive fatigue testing. We used a tracer double label water. which is the gold standard to get total daily energy expenditure. There was interviews for the psych social program and then Susan and their team were sorting out all the energy intake pieces as best as possible so that once the six day event started, they were up to speed. In the race daily, there were options for blood collections, double label water, dietary intake. had GPS and heart rate. We had continuous glucose monitoring. going on core temperature monitoring with a, a squalible pill. We use it or a smart ring. We had inertial measurement units. So IMUs are little sensors on the shoe and in a pocket in the shorts. So it basically measures in a triaxial direction, the bounce. And so from that bounce, you can then assess foot strikes, foot length, number of steps taken. We had an entire biomechan tent set up. with force plates and motion capture. So they just ran through the tent that produced almost a terabyte of data. And then psych social observations throughout. So, and then there was post testing, which is pretty similar to the pre-testing I highlighted. So it was a big range of what we did. Yeah, that's a that's a ton of info. I think it's also important to say that we did that on the side of performance. Like we were actually off to the side and as unobtrusive as we possibly could be. So that the athletes really were there to run. They were there to run. So, yeah. And I might add to that, Susan, that's a really good point is at the female athlete conference earlier this year, there was a panel on this and the three athletes that showed up and came to that panel. All of them echoed that, that they felt the science program was an add on and it wasn't necessarily a distraction. And I think a huge piece to that is every athlete brought five to seven people that were part of their crew for six days straight. And we really access the athletes. and delivered almost all of this through the crews. like our crews were the, you know, we go there first, where are they at? Okay, what's the battery on the aura ring? Can we switch it out next lap? Are they going to come in for a break? Do we need to add another core temp pill? Where's the battery on the continuous glucose down? You know, so, you know, there's check-ins throughout, but that also required then 28 staff on shifts that we had three different base shifts that went. 24, 24 six. So everyone had overnight shifts. Everyone had some time off to try to rotate through skills, but it's also was logistically challenging because, you know, Susan's amazing and energy intake, but we can't put her on the biomech tent and we can't take someone from the biomech tent and put them into energy intake. know, like everyone also had their own background and skills to, to be able to do what they needed to do. Wow. This is, this sounds so fascinating. Also fun. Was it fun? It sounds fun. Very cool. okay. So I'm curious, how did, how was the event, the six day event structure? these athletes like sleeping and like at the night or were some going through the night? What did that look like? Yeah. Well, I think the main thing to say here is that there was one rule, which was walk or run as far as you can over the six days. so athletes could choose to sleep and eat whenever they wanted. So the course was a loop, which allowed for the athletes to have a pit area, like a Formula One. kind of style pit area or crew where their crews supported them and they were able to go in and rest and recover as they needed to. And then also there was also another athlete aid station at the two kilometer mark. So there was a lot of opportunity for athlete support. And then they chose to run or walk or sleep or eat as they needed to. Yep. Okay, awesome. And I think it's a two, you said it was a two and a half mile loop. Yeah, or 4.1 kilometer loop if you're a Canadian. it was like 2.476, whatever. I will highlight that two different course certifiers were there to make every record eligible en route because you have 12 hour, 24, 48 multi-day records, but then you also have distance records. And you have people coming on and off the course. right. from a timing map perspective and then figuring out all those records. Even the logistics around that is quite extensive and tricky, but it was all validated, all confirmed. like, you know, there's a representative from USA Track and Field, Anti- Doping was there. did anti-doping tests pre and post as well. So it was a legit event. Incredible. And tell us a little bit about the terrain, the location, the temperature. Was this at altitude? Tell us about that. What was that like over the six days? Yeah, the event took place at Lake Cahuilla, which was in California, and it was a loop around a lake. So I think it was about 80 % gravel and about maybe 20 % paved and a little bit sloping, little not, it was mostly flat, but not completely flat. So that I would say that's the main thing about the terrain, the athletes. mostly liked it. There was a little one section I think where they didn't love it because it was a little bit soft but I think otherwise it was pretty good and Trent will probably tell you that they searched long and hard to try to find em something that fit for all 10 athletes, a course that was em high quality enough that some records could be broken. But that was also interesting and didn't cause too much neuromuscular fatigue, etc. And there's a lot of things that went into this and that was not my area, but I'm sure Trent could talk quite specifically about how long they looked for a proper location. em So Trent, did you want to say anything more about that or? You know, you're looking at a location that checks a few boxes. One in terms of terrain, environmental project, projected environmental conditions. You don't want it too hot. You don't want it too cold, kind of goldie locks. But there's some athletes that would rather do a six day ultra on a 400 meter track. And then there's, there was other athletes that would like to run in the mountains for six days straight and never cross the same path. rate. And so you're trying to thread the needle between those dynamics and then also have a place that was, and it was, it was just stunning. It was beautiful. Now, interestingly enough, and this came up in our panel and that project further, or at the FEMA Athlete Conference as well in Boston, as yeah, we were entering into their windy season. It wasn't supposed to start until April, but. two or three days before the event, was this huge massive windstorm, which actually caused like a whole bunch of damage and issues and some athletes were supposed to land that day and their flights got delayed a day. so that that's field-based research. eh The entire plan that we had and all the schedule, we just ripped it up and almost started over two days out again because we had to move the media day and we had to move interviews. We had to move course recon. We had to move where the crews were gonna see the course. had to move meeting times and while rebuilding parts of the course that were already pre-set up. I had no gray hair prior to this event. I'm kidding, I did have gray hair, but there were some times I was like, what have we gotten into here? But in the end, there were a couple of days where it did rain or get a little windy, but it was nothing like the few days before. I think the vast majority of the event, the weather was pretty good. Yeah, nice. Do you recall temperature ranges like highs and lows out of curiosity? And you can give them in Celsius. I mean, I remember the average is around 20 degrees. I think maybe it got as hot as 30, but it was full sun, so it was warm. ah And in fact, and then nights, it was in the desert, so it was also cool at night. ah But that allowed, we ended up having about 35 % of the running done at night, I think because it was full sun and it was pretty warm in the day. ah I know that I was never so happy as when one of the Lululemon support staff brought me one of their puff jackets because it was cold supporting the athletes at night. so yeah. But yeah, the multi day stuff is very fascinating. All the different and I mean, especially too, when there's like altitude involved and yeah, all the environmental conditions very fascinating. Okay. Well, I want to dive into nutrition. So Susan, we're going to do a deep dive here. You mentioned you were trying to be kind of like out of the athletes hair. Does this mean that they were allowed to fuel like whenever they wanted or were you guys providing specific nutrition throughout? Well, there were no constraints. mean, unless the athlete asked for something that we couldn't source, but we absolutely did our best. had somebody who was a runner and if we didn't bring it with us, they would maybe go look for it. But we did a lot of reconnaissance work in advance, spending some time talking with the athletes to try to find out, you know, what kinds of foods that they would like to eat. As I said, we had athletes from all over the world and so some of the food likes were different than, let's say, your typical North American. So we wanted to understand that. And then we had a wide, wide variety of sport drinks and sport foods. We had a whole shelving unit set up with sport drinks and gels and treats and snacks. And then we also encouraged the athletes to bring their own favorite foods and some of them did some of the meal prep on their own with their staff or with their crews in their tents or their trailers. But we also brought a performance chef and they had a team with them. And so we had somebody available to cook for the athletes 24 hours a day. So if the athletes, know, as they were running around had a craving for pierogies, which happened quite regularly, they would run through their They would run by their crew area and say, need some pierogies, on my next lap. And we would relay that to the chef and they would prepare that and it would be available the next time the athlete came through. yeah, they pretty much ate whatever that they wanted to. But then having said that, if an athlete was struggling, we also would give them some information and support to try to help them along. to make sure that they were trying to minimize some of the energy deficits. So yeah, we did allow them or we did support them if they had questions and often it was through the crew as Trent said, but yeah, anything went. Wow. And so how are you measuring energy going in and energy expenditure? Why don't you do energy in, and I can answer the energy out. sure. So are you asking about how we measured what the athletes were taking in? yeah, okay. So basically every single morsel of food was weighed before they ate it. So some of the foods were recorded as like each individual portion. So if it was a burrito, we measured each item that went into the burrito and then they would eat what they wanted to. And then we would pick that apart and reweigh that. If it was like a lasagna, for example, we would use the weight back system, which meant that they would, we would pre-weigh the food and then they, would measure the plate waste. And then through the day, if let's say some athletes, ate a lot of gels, their team would keep all of the wrappers and then we would get the wrappers at the end and we would note that they had, let's say, eight Morton's gels that day. And then we would log that in. And we used the researchers to do that, but we also used the crews and we used the chef and his support staff as well. where they would write down on paper or they would use an iPad and smart sheets or they would take photos. So we had lots of different available ways to track the pre and the post. So I wanted to be as accurate as possible. Yeah. Yeah. but picking apart a burrito and its components sounds like quite the job. Yeah, well, I guess if you want high quality data out or information out, you have to get high quality information in and unless you're accurate about what you're collecting, it's not worth doing because otherwise we wouldn't be able to with confidence tell you how many calories or what the total daily energy intake of an athlete was if we didn't do a good job on that. Yeah, yeah, no, this is amazing. mean, very. Yeah, I'm I'm excited to hear more and what you guys found. But Trent, I'll let you break down. How did you measure energy expenditure? Yeah, first, I want to compliment the energy team, Sarah Purcell, Sarah Craven, and Susan. The three of them really drove that. had other people helping, but I'm going to say by far, it was the biggest work of all the groups. em It's the easiest on paper, but what you've just heard, it's really challenging to consistently do for six days straight. A whole other thing to do it for a two-day project or something, but Yeah. Yeah. Yeah. I have to say though, Trent, that we had such great support from the crews, right? If they wouldn't have been able to be on board, it would have been a much bigger job. yeah, we have to kudos to the crews. Yeah. Yeah. Yeah. Yeah. were great. So on the energy balance is energy intake, which Susan just described versus energy expenditure or total daily energy expenditure. so total daily energy expenditure can be measured indirectly with double labeled water. And so what they do is they have a labeled oxygen and the labeled hydrogen in the water that you drink. And when we collect the athlete's urine, we can measure oh how much of the labeled hydrogen ends up in H2O in the urine and then make a whole bunch of calculations. oh It's quite expensive, expensive urine and expensive water to then calculate the total daily energy expenditure. Within total daily energy expenditure, there's different components. There's four different components. There's the exercise energy expenditure. There's the non-exercise activity energy expenditure, which is walking around or working or talking. There's the basal metabolic rate, which we measured pre and post in the lab resting metabolic rate. And then there's the thermic effect of food, which is the energetic cost to process food to make energy. And so there's always an estimate of about 10 % on that. We measured basal metabolic rate. We measured total daily energy expenditure with the label. We measured energy intake. We have a very strong estimate for the thermic effect of food. So the only thing left over is exercise energy expenditure. we measured the exercise energy expenditure by subtraction, but we've also done it. Indirectly by heart rate and speed bands based on the testing we did in the few days lighting in, because we had a metabolic heart, we were measuring the core cost of exercise and the heart rates. And we have walking data all the way up to running data. So we can back calculate that through the entire event for every athlete. and then we also used, some different, estimates like metabolic equivalence, heart rate equivalence and other ways. So part of the paper will be. showing the four or five different methods across all of these ways to estimate energy expenditure and then highlighting over a six day event, which one we think is most accurate. So I got a little nerdy on all the inputs there, but I think, yeah, it's important for the listener to understand the rigor that goes into doing these projects. Yeah. So with the doubly labeled water within the urine, that mean every time the athlete has to use the restroom, you're collect like they have to go to a specific location because you're collecting their entire six days worth of urine? Great, great question. No, we did it in two, three day chunks. We got that with a baseline urine. So they produced a clean sample prior to drinking the water. They drank the water. We then got a sample three to four hours later. So we had the peak amount of tracer in the urine. We got a sample on day three. So we could look at the total daily energy expenditure over the first half of the race. Mm. And then we got a sample at the end after day six. So we could look at the second half of the race. and generally speaking, double label water, you can't get energetic resolution over hours. It's usually you need a few days for, for, for the method to work so that that fit really well, well for us. Yeah. But yeah, especially at the end of the event, during the celebrations, like there was a bunch of us had, well, one, someone brought mimosas. So I have this picture of me drinking. champagne orange juice in this hand and then I had a urine sample in this hand. Oh no, hopefully the six days of fatigue doesn't like catch up. Yeah. I did have a question to doing a multi-day event with the, m was it the temperature sensor you said they swallowed? How do you know when that's out of the body? Yeah, don't, it's one single use only. Let's just be clear here. We're recycling those. Yeah. So you can also get temperature live. So there's a Bluetooth feature to it. So you can see with the sensor, as soon as you get close to the athlete for, well, it takes maybe 30 seconds or one minute, but when they come in for a break at the pit stop, our wearables team, we had a team just based on sensors, would go and see where they're at. but we also proactively gave extra swallowable sensors the size of a small, like almost like a fish oil capsule, a little bigger than normal. And so you could tell right away when they were excreted, but we then would have another one in there. So in many instances, we'd have two measuring within the intestinal tract within the system at any given time, just in different thoughts in the intestinal tract. Wow, that's so fascinating. All of this is so neat. Like nerd out on all this data. Okay, so you got tons of data. Are you guys able to share? You said it was just an abstract that's out. Are you able to share what you guys discovered so far? Yeah, like we've shown the data at two conferences now that the top level of kind of physiology data and I can highlight in the next couple of years is probably going to be eight papers published on different areas. We have an overall methods paper that we've published already. And then we have the capstone paper that's in review right now. So the capstone paper is the top level methods and overview of what we saw that integrates kind of like the highlight reel for each group, but not the details. Because in each research group, whether it's energy or biomechanics, we'll do a very several specific papers on what they found there. So from the nutrition caloric top level perspective, and in the abstract that you saw and what we presented, can give. give the listeners a little bit of a low down here and a bit of a highlight reel. So first of all, know, athletes ran anywhere from 200 to over 900 kilometers throughout the event in six days, which for all of them is just completely amazing. And there was a really neat, very tight correlation. The more you ran, the more you ate. And so people really did self-select even on a day-to-day ratio. Yeah, the more they ran, the more they knew to eat. so I think part of that is experience of athletes. Part of that is coaching from people like Susan. And I think part of it's just innate in human biology. know, when you're in an energy deficit, there's signals to eat more. m What else is new or what else we found, which should make sense is the, again, there was a very good correlation, significant correlation between total distance run. and total energy expenditure. So as I said, total energy expenditure and intake and distance all were, were related. And I should highlight that on the exercise on the energy expenditure, on average, athletes expended 7,000 calories a day. I'm double using the double label water, but we had three female athletes that recorded the highest energy expenditures ever recorded in the literature. they kind of set metabolic world records. So. Um, we had, we had one that averaged 7,600 calories a day for six days straight. One that averaged 8,800 calories a day for six days straight. And then one that averaged 11,300 calories a day for, six days straight. it was just phenomenal, phenomenal energetic output over that, over that six days. that did result in an. on average, a negative energy balance of about two and a half to 2,200 calories. Like you just can't eat that much over the six days. so, there was definitely negative energy balance throughout. a few athletes popped into the positive uncertain days that were doing less mileage, but, generally speaking, yeah, throughout the six day event, there was negative energy balance. And again, despite what I just said, athletes that went further eight more. Mm-hmm. However, athletes that went further also had more negative energy balance. So you just can't, when you're expending 11,000 calories a day, yeah, like, you know, that one athlete was still eating probably six or 7,000 calories a day, but there's still a 4,000 calorie a day gap. And so those are some of the outcomes that we're seeing that will be in this capstone paper that is in review. Once that's out and published, there's a whole bunch of other details and maybe we'll have to come onto your podcast again and talk a little more about the details. We're reticent to discuss more until the paper is accepted and those details are out in the published literature. Yeah. Are you able to share the individual that was expending over 11,000 calories a day? Was that the person that was also covering the most mileage? Okay. Okay. and, and yeah, like all this is done under, under ethics and anonymized athletes, but, they also know, and it was written into their consent forms and their ethics, you know, you're in a 10 day race with lots of media, media coverage. So people are getting that in some instances, figure out who you are. And most of the athletes were like, no, I want to promote this on social media. And so, yeah, that top top athlete, I mean, you can Google search it. It's Camille Herron and she was. It's absolutely mind blowing, phenomenal in terms of the 901 point whatever kilometers she covered in six days for a new woman's world record. Wow. Did you guys monitor fluid consumption? Well, we monitored everything. although off the top of my head, I don't know how much she actually drank. We know how many calories she ate every day and we know what her energy deficit was. We know what her macro intake was. And we probably somewhere have that data on her fluid intake. Yeah, just off the top of my head, I don't know what it is. That and did you guys I forgot to ask this. Did you guys take into consideration or observer note menstrual cycle phase? Yeah, so I'm going to raise my hand and say I'm on a whole bunch of papers highlighting how important it is to characterize every single piece of the menstrual cycle. In those same methodological papers, there is an appreciation for the challenges that present in doing that in the field and outside of the laboratory. So we do have questionnaire-based data on the athletes and where they were self-report in their menstrual cycle. But I'll also highlight that the average age of the athletes was into the early to mid 40s off the top of my head. yeah, some of the athletes were already peri and menopausal. So you can't report that. they said, yeah, they don't have a menstrual cycle. So yeah, we only ended up with a a small handful of athletes were pretty sure of their reporting. That said, what's interesting is there is a massive deficit, but it does appear from a health perspective, everyone has bounced out of it. Okay, every single athlete has undertaken races again. There's no long-term signs of any deleterious outcomes from the event itself. And so, yeah, those were really positive things. And then about a year out with the athlete screening, the Canadian Sport Institute Pacific provided holistic services to these athletes that they could opt into. you if they wanted to consult with Susan on nutrition for the year and a half leading in, they had that option. If they wanted physiological or training consults from me and our team, they had that. We did through another research project, a REDS medical screen. And yeah, generally, generally speaking, this was a pretty, pretty healthy group in terms of that screen. And, I want to reiterate what Susan highlighted earlier. and sorry, I'm verbose here, but, normally there's a 10 to 20, 30 % injury rate for every athlete in a year. The fact that we got 10 athletes, we supported them. had 10 athletes reach the line, 10 athletes finish, 10 athletes reach their goals. Several athletes set world records as Beyond all this caloric energy expenditure stuff, that is a mind blowing to me that we were able to deliver that with those athletes. yeah, that is such a neat outcome of this project. Yeah, I think that says a lot. Like when people are being supported and have a team of people who know the specifics about different aspects that they maybe don't, it can help support them for a good amount of time leading into something I think makes a big difference. So yeah, kudos to you guys. that are willing to take on the information and learn from it. Yeah, I think there's a couple of other pieces I'd like to highlight around the menstrual cycle though, for example, is the event took place when the event took place. And so really if an athlete was menstruating or not menstruating, if they were a naturally menstruating female, we don't have any control over that. So all that we can do is what Trent said is just ask the athletes to track or to fill out questionnaires. So I think that that's an important piece of the menstrual function to keep in mind. And so I imagine you got information if anybody was on hormonal birth control as well in the questionnaire. Yeah. Awesome. With the behavior piece, I know you guys weren't the behavior side of things, em was there, like, did you see any struggles throughout the six days? Or even just any physical issues em occur with the runners, GI, anything like that, cramping? Back on. We did do some GI screens. ah We didn't get data every day, but we tried to get data on a regular basis. And we definitely did see, as you do in any endurance event, some GI struggles. And we were there to support the athletes that did have that. So with making recommendations for what kinds of foods maybe to try eating. But we definitely did see some GI struggles. And Trent, you could. talk about the cramping and I know we did have one athlete that had a muscle or a hip issue that was supported throughout the event. Mm-hmm. Yeah, so I mean, with this event as well, had three separate physicians involved. I mean, that athlete to physician ratio would never be better in all three physicians. One was the head physician for Western states, Andy Pasternak. One is a lead physician at the Stanford Women's Faster Program, Emily Kraus Yeah, yeah. her on a few times. She's wonderful. Yeah. And the third physician's a Harvard physician that is one of the lead physicians at Burning Man. So he's like big event medicine. So when you think about the three skill sets, it was really awesome when they were all complimentary to each other. and because we had this research program, we're also able live in the moment monitor how the athletes were doing. So to give feedback to the physicians or their crews, like, Oh, look at their, their blood sodium's here or their creatine kinase has gone to here or what have you. So, you know, that was indirectly from the research program, another layer of kind of safety involved. And I'm pausing, Susan, you pitched me something and I totally forget what your question was. Oh, well, think your question, Kyla, was related to muscle or muscle issues. Yeah, so I did pitch that to you. for sure, there were some individuals that were working through some muscle issues and some muscle challenges. we, we on certain days brought in, physios and massage therapists to the event. then we actually had two different physiotherapists that were in the biomech team that also helped do not only biomech, but actually said, you know what, I can help here. They stepped in and helped out with some physiotherapy. And so there, I think overall some every athlete set their best distance or what they were hoping for. But I'm, I think a couple of athletes probably could have went a little further, but yeah, I mean, 10 athletes, six days, you're going to have a, have a few niggles show up, but they all finished running again together and smiling at the end. So at the end it all came together. That's great. Are you guys able to share any info on the body composition changes throughout the six days? I can speak to it a little bit. And it's mainly going to be a little bit of a technical discussion. It's going to blow you away. I know I just said, like on average, people had, you know, a negative energy balance of two to 6,000 calories a day. The body weight changes for you to post as a group were not changed. And that has been shown in several studies in multi-day ultras, or if you talk to grand tour cyclists, after a day off or when there's a, when heat comes through, there is a whole bunch of water retention that happens in multi-day ultras. And, and so when they came back in for their body composition and body weight after the event, we have another way to actually assess and indirectly look at blood volume and their blood volumes went up. anywhere from 20 to 40%. That's mainly that, that water retention piece. And what's thought is, because of extreme dehydration or heat through multiple days, yeah, your, your kidneys, send out a whole bunch of hormones, you know, renin, basopressin, aldosterone that tend to send a signal. I'm, I'm dehydrated. I better hold on to all water that I have. And, it can cause some bloating. legs are thicker, their feet are fat. so at a body weight perspective, on average, there was no change. The other way that we look at body composition is through DEXA scans. And we had DEXA pre when they're all under resting conditions, we didn't even attempt a DEXA scan post, because it violates all the methodological principles of getting a good DEXA scan. which means you should be in good neutral hydration state and in a resting conditions. Well, we're not gonna hold the athletes there for three or four days afterwards to get a DEXA scan. So long story short, they were in massive energy deficits, but it doesn't show up in body weight losses because of this acute effect of hyper hydration and pretension of fluids, yeah. oh Do you think from a recovery standpoint that that is favorable? Like the body's doing that? And does that help recovery? Or should athletes like if they feel bloated like that, should they be trying to get that water out? So it depends on the context of your question. I firmly believe through millennial that mother nature knows what she's doing just as a principle. So yes, I do think that there's a recovery piece there that that mother nature knows knows what she's doing. However, this can also happen on rest days in the middle of the tour de France. And a lot of riders on rest days don't rest. They still ride three or four hours that day. And I suspect they do that. because of this reason, they knock down, they sweat out some of the fluid, they get hyper responses on the glycogen and usually coming out of a rest day on the Tour de France, it's in the mountains and they're gonna go straight uphill the next day. having a 4 % increase in body mass due to water weight is probably not good from a performance perspective. I'm speculating here, so I think it depends on the context of the situation. Wow, yeah, so fascinating. Okay, well, I want to be mindful of your guys' time. Is there any other nuggets you want to share about the further study? I think, Susan, I think we got the highlight reel. yeah, I think so. think the main things for me were the level of energy deficit. em Obviously, you wouldn't be able to continue to sustain that over more than six days. I think you're pretty much getting close to the maximal ceiling that an athlete can be in such a deficit. em think maybe Trent, one thing that was found was that the neuromuscular fatigue piece. I don't know if you're able to speak about that. I think that was pretty fascinating. Yeah, so that's true. And that's led by Chris Napier and Nick Bruce, Dr. Nick Bruce, she just defended last year. So what they did is they had a contraption that they brought down that does maximal voluntary contraction where they actually stimulate the muscle. So it's not like a cattle prod, but it takes the brain out of it and they can get a maximal voluntary contraction. And they looked at that on a force plate. indoors fresh and then after the event. for the legs, there was no significant deficit. And there is data, thank you, Susan, for highlighting, there is data in women to show that women compared to men may have a more protective effect and more resiliency to neuromuscular fatigue and Wow. We don't have an N equals 10 male cohort going at the same time. That would have been really neat. anyways, that was quite astounding. In the arms, they did show a deficit. So that's up to Chris and Nikki to tease out. That's their research area. But yeah, that's an interesting outcome for sure. That is fascinating. Wow. guess one thing we didn't highlight was the minimal sleep that the athletes got. At least I don't think we talked about that. I mean, I think they were averaging about five hours a night, but one and a half hours a night for one of the athletes. I think that what does that, that's how many, that's nine hours over the course of the event. Dang. I think the maximum was like 41 hours over six days. So we really also saw very limited amount of recovery time. And so for them to have done what they did with energy deficit and kind of limited amount of sleep and recovery really, when you stop to think about it, it's kind of, it's mind blowing. So, yeah. You didn't happen to measure like protein synthesis or mitochondrial. Okay. did not, that would directly require a muscle biopsy, indirectly requires another quarter million dollar in protein tracers, which we didn't do. Yeah. Wow. Gosh. Yeah. ah Okay. I have one last question. Speaking of all that, if you're allowed to share this part, creatine kinase levels, you drew that, was it immediately after the six days? Yeah, so there was a significant relationship between daily distance and creatine kinase. So the more you ran, the higher your creatine kinase. You know, there's some of the highest creatine kinases I've ever seen. So one of the athletes peaked out on day two and three approaching 10,000 units in terms of creatine kinase. What was interesting is by day four and five, she was down to 7,000. 4,000 and then post race down to just under 2,000. So you can see an adaptive effect of creatine kinase within the race. Almost all athletes look like that. It peaks at day one or two, and then it's coming down over the U.S. six days. Most of the other athletes were all under 2,000 units for creatine kinase. A couple were above that. I suspect creatine kinase will also be really significantly correlated to the eccentric component of a course, the downhill parts. And because our course was very flat, a lot of these creatine kinases weren't that huge except one or two of the athletes that went really well. If you measured it at Western States. So the doc there was like, these are pretty low compared to what I'm used to at Western States with all the downhill pieces. yeah. And the body is, I mean, it sounds like it's like adapting to that and clearing that out over the coming days. Like, it's pretty incredible. Wow. That is a marker that I think is fascinating where I've had clients who will come to me and they're like, PCP does their labs and like that's elevated because they took it right after like an Iron Man race or something. The doctors. a little going what's going on. Yeah. Yeah. we need to put you on a super low protein diet. Don't take your creatine. I know it's totally yeah, if you want to speak on that, I'd love for our listeners to hear your your input or thoughts on that. I would just not take that test right after doing that kind of a race. I would just do your blood work once or twice a year, your baseline, and then that's the best way to do it. I don't think we really, it's interesting information, but I think your general listener doesn't need to know what their creatine kinase levels are. Yeah. Do you have a recommendation of like rest days prior to a blood work or how long it takes for those levels to normalize after a hard effort? Well, we definitely recommend a rested blood work and usually we're looking at 24 to 48 hours if we can have that. Sometimes we don't get that, but we're then looking at having our athletes not do a hard training session. So to answer the question about how close proximity to after a hard training session, I don't know what the best answer is there, Trent, do you? I think it depends on whether or not that hard training session is routine for that athlete. That's the really big piece. So if they're used to running hard for one hour, three times a week, their creatine kinase is barely going to blip because that's what they're used to. If you take someone new and you have them do a one hour run, their creatine kinase is going to go through the roof. So it depends on their history and where they're at. Usually we try that 24 to 48 hour clear window. It helps with iron measurements as well, because there's not elevated exudin and elevated ferritins. You get a first thing in the morning, ideally with about the same hydration factor and pick the same lab. Lab to lab differences can be quite large. So no matter what you're measuring, ideally it's going to that same lab. Yeah, that makes that's lot of good suggestions there. Okay, I'm going to jump back to your two truths and a lie and we are going to find out some fun facts. Okay, so Susan says the world consumes 50 billion burgers a year. All further athletes ate burgers and classic burgers are also known as the California burger. I thought the 50 billion burgers a year was a lie. Is that correct? That's the truth. I know crazy, hey? The further. Yeah, so we actually had one vegan athlete. So yeah. Okay. No burger for the- but did everybody else eat burgers besides the vegan? Pretty much. We did some pre-testing as Trent mentioned. We had a chef set up then, but then they had to move their entire kitchen facility to another location. While they were doing that, there was a little tiny bit of a window and we went for in-and-out burgers for the athletes. And then Trent, you said during the peak of the Seattle grunge Rock area, you had dreadlocks, six tattoos and a nipple piercing. I'm thinking the six tattoos was a lie. Which one was your lie? right, I only have one small tattoo on my leg, so... Yeah. oh was a nipple piercing and dreadlocks. Yeah, yeah, and don't do this at home. I went to Woodstock 99, because I went to stay at school at Cornell, which is like quite close to, and I got that piercing like two weeks before going to that. This is dumbest idea ever. And it didn't get infected. I have no idea how that didn't happen. So there you go. is impressive. Wow. Okay. Well, this has been super fun. Where can our listeners find you, follow you? When is this doing, when do we think this paper is like officially getting published? Do we have an idea? That's a tricky estimate. I've had papers published in two weeks to eight months. It depends on the number of reviews. It depends on what the reviewers think of it, how quickly they do the reviews, how many review cycles we have. next four plus or minus two months. Yeah. Okay. Great. are either of you speaking to any conferences coming up in 2026? I'm not. have a slew of them. Yeah. Yeah, I'll speak at the American College of Sports Medicine Conference. That's in Utah and then the International Society of Sport Nutrition in Florida as well. I those are my two US ones. I have one in Germany in March, but that's a translated one or whatever. Awesome. I might see you at the ISSN one. I'm going to try and go to that. I'll have to pop in and say hi. And then Susan, where can people find you? Follow your research. Are you taking on clients? I don't take on clients because I'm 100 % subscribed to Canadian Sport Institute and I'm generally not really much on social media. So I think if you want to follow my research, you're following Trent's research because mostly everything that he's doing, I'm in the background supporting, well, not mostly, some of. So yeah. So perfect. Well, this has been super fun and fascinating. Thank you both, Susan and Trent, for joining us. This has been wonderful. Yeah, thank you very much. It was a lot of fun. Thanks for inviting us. You bet.

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Kyla Channell, MS

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